Abstract Conceptual models of the fracture networks in shale were evaluated at a site contaminated with chlorinated solvents. Prior borehole testing in eight holes under open hole ambient and pumping conditions identified 14 flow zones (140 m bedrock interval) with zero to five zones per hole. Cross-hole testing showed only a few cross-connections between transmissive fractures. The initial conceptual model thus featured a sparse fracture network with few dominant fractures. Detailed profiles (hydraulic head, rock core volatile organic compounds, groundwater volatile organic compounds from packer and multi-level sampling, cross-hole multi-level monitoring of permanganate injections) were collected from several holes and indicated a well-connected fracture network with many hydraulically active fractures not influenced by open hole cross-connection. This contrasting conceptual model contained numerous well-connected horizontal and vertical fractures that allowed chlorinated solvents to penetrate the upper 50–60 m of bedrock as dense non-aqueous phase liquids, followed by diffusion-driven mass transfer from fractures into the porous rock matrix, such that nearly all the contaminant mass resided as dissolved and sorbed phases, measurable in rock core without cross-contamination during drilling. The difference in the two conceptual models has important implications for source zone and plume attenuation.

Abstract The United States Army has been a functioning entity for nearly 240 years and throughout those years has faced changing military threats. We focus here on when, where, and why military installations, primarily those of the Army, were created and placed on the landscape, and we examine some of the ways in which their situation changed as the country shifted from a domestic protection stance to a more internationalist projection-oriented operational philosophy. The 1790s, the 1890s, and the 1990s each presented challenges—but of very different types. Were we responding to external or internal threats? What were the needs of the era? Were they focused on materiel production, on leadership and training, on protecting our coastlines, on protecting travel routes within the country, or on preparing to project force hundreds or thousands of miles outside the United States? At one time, one or more of these differing concerns were the driving reasons behind the establishment of a military installation. The current “landscape” of installations reflects a response to these differing threats across our entire nation’s history. This is why the U.S. Defense Department has recently been reviewing the inventory of military bases, to determine if they are all still relevant and useful. Do we now have too many or too few installations? Or, are they in the wrong place to answer the current and emerging threats? Finally, what happens when an installation is believed to no longer be needed? When and how may an installation be converted to another life?

Abstract Afghanistan is a mountainous, arid country with limited surface water supplies. The complex geology in this country includes active tectonics and mountain ranges. Afghanistan is subdivided into three distinct hydrogeological areas: the Central Highlands, the Northern Plain, and the Great Southern Plain. Most groundwater is located in the Central Highlands, where water of sufficient quantity to meet the needs of the population is available primarily by digging wells into unconsolidated alluvial aquifers located in mountain valleys. A lack of sustainable, high-quality water supplies can have a negative impact on the ability to conduct military operations. An understanding of hydrogeological conditions is required in order to minimize exposures to natural and anthropogenic sources of contamination that may pose either acute or chronic health risks to military forces. This same scarcity of potable water can have a negative impact on the local population. Projects that improve the quantity and quality of water available to both military forces and the local population are important to improve the overall stability of Afghanistan.

Abstract U.S. military installations increasingly have become de facto bioreserves as the result of legacy and current land uses, urbanization, and historical siting of installations. The relative value of military lands as bioreserves compared to land holdings of other federal agencies is not proportional to total land area. Ironically, a significant reason that U.S. military installations have become important bioreserves is that they were not established with the purpose of conserving or extracting natural resources. This historical factor has resulted in a broad representation of U.S. ecoregions on military lands and largely has shielded those lands from the habitat loss and degradation that has occurred in surrounding regions due to urbanization, agricultural development, and other non-military land uses. Fort Hood, Texas, is used as a case study to illustrate the characteristics of military installations that fit the model for bioreserves as areas for conservation of biological resources and processes in the context of human use of the environment. A major current challenge for management of natural resources on military lands is that the value of U.S. military lands as bioreserves is increasing as surrounding habitats and natural communities continue to be degraded.

Abstract Department of Defense military land use of the desert southwest includes a wide spectrum of military weapons testing, force-on-force training, and various types of flight training. The desert southwest provides a critical asset for the U.S. military— open space. Installations in the desert southwest tend to be much larger than installations in other regions of the nation, with several exceeding 400,000 ha. This open-space asset has allowed the military to historically establish large training areas and ranges on installations and to define expansive air maneuver regions above these ranges and above the vast public lands of other agencies. It also offers critical training and testing areas that are analogs to similar worldwide environments where the military operates. Training and testing activities are conducted in the three-dimensional land and air space that replicates the modern battle space. Land and air space use is highly variable among installations depending on mission requirements. Natural resource management challenges include the large spatial extent of lands and air space under Department of Defense management, highly variable military land-use requirements, significant endangered species regulatory and conservation requirements, encroachment and Base Realignment and Closure requirements, competition for water resources, and climate change. Department of Defense natural resource managers attempt to meet these challenges through interagency cooperative agreements, integrated natural resource management plans, and Department of Defense sustainable range programs.

Abstract Gullies are common features throughout the southwestern United States including Army training facilities such as the Pinon Canyon Maneuver Site. These gullies have depths up to several meters, which can restrict the mobility of troops and vehicles during training exercises. They also have the potential to grow in size, which can degrade training lands. At the upstream end, gullies usually begin with an abrupt headwall, and in the downstream direction, gullies also tend to terminate abruptly. In this paper, we hypothesize that the small extent of convective storms and significant transmission losses in channels promote the downstream disappearance of gullies. The role of these factors is tested by applying a geomorphic model in which storms occur within circular portions of the simulation domain and channel flow is lost to seepage up to a specified infiltration or seepage capacity in each grid cell. The net effect of these processes is to reduce the sediment transport capacity in the downstream direction relative to the case with an infinite storm size and no channel losses. The reduced sediment capacity alters the relationship between slope and drainage area for topographies at equilibrium. In addition, limited storm sizes can also produce disconnected areas of incision within generally depositional portions of the landscape.

Abstract To assist U.S. Air Force archaeologists study and preserve cultural sites associated with early Native American inhabitants of the Nevada Test and Training Range, we have determined the late Pleistocene environments of nine playas on the range from surface deposits around the playas. Based on shoreline features such as barrier bars, wave-cut benches, and beach gravel deposits, the playas of Mud Lake, Gold Flat, and Kawich Lake contained pluvial lakes. Based on fossils, palustral clay sediments, paleospring, and seep deposits, the playas of Stonewall Flat, Indian Springs Valley, and Three Lakes Valley contained extensive wetlands. Two playas in Cactus Flat and one at Dog Bone Lake contain none of these surface deposits and are interpreted to have hosted seasonal lakes and grassy meadows, based on modern analogs in the Pahranagat Valley. Radiocarbon dates from Mud Lake, Gold Flat, and Stonewall Flat indicate these environments existed up to the beginning of the Holocene ca. 10,000 years before present (yr B.P.) and would have provided resources of fresh water, fish and game, edible and medicinal plants, fuel, and materials for the construction of shelter. As changing climate conditions from 10,000–8000 radiocarbon yr B.P. forced the contraction and eventual disappearance of these lakes and wetlands, basins with larger surface water budgets probably furnished early inhabitants with useful resources after the pluvial features in the smaller basins had disappeared.

Abstract This book, generated under the auspices of the Geological Society of London’s History of Geology and Hydrogeological Groups, contains 20 papers from authors in the UK, USA, Germany and Austria. Historically, it gives examples of the influence of groundwater on battlefield tactics and fortress construction; describes how groundwater was developed for water supply and overcome as an obstacle to military engineering and cross-country vehicular movement by both sides in World Wars I and II; and culminates with examples of the application of hydrogeology to site boreholes in recent conflicts, notably in Afghanistan. Examples of current research described include hydrological model development; the impact of variations in soil moisture on explosive threat detection and cross-country vehicle mobility; contamination arising from defence sites and its remediation; privatization of water supplies; and the equitable allocation of resources derived from an international transboundary aquifer.